The present invention relates to a system of washing cans and, in particular, to an improved system for washing the inside of cans.
The washing of cans to remove lubricants used in forming the cans, debris, and other contaminants is usually done by passing cans over and under fixed spray nozzles. The cans usually are moved by a moving horizontal belt. There are also washers which use pins on which the cans are placed to move them vertically and horizontally while spray nozzles are used to spray the inside and outside of the can. There are also washers where the cans move horizontally on a belt or other device that moves the cans. In this case, the nozzles are horizontal for the interior wash and outside bottom wash, and vertical or partly vertical for the exterior wall wash.
All these systems use a large number of nozzles with relatively small orifices, and produce a fine spray. In all of these systems the interior washing of the can takes place in a random fashion since the cans and nozzles are not synchronized and the spray hits the interior of the can at various points.
Due to this random spraying of the can interior, the lubricant and/or other contaminants are randomly moved about the interior of the can, and their complete removal requires a spray time of 10 seconds or more depending on the number of nozzles and the rate of can washing. For cans being washed at a rate of 500 per minute, several thousand nozzles are used and the wash time can be as long as 20 seconds or more. This results in a cumbersome and expensive system. (The outside of the cans are also usually washed randomly with a fine spray.)